CVE-2026-9058 CRITICAL

CVE-2026-9058: Improper Certificate Verification in Szafir SDK

Vendor Krajowa Izba Rozliczeniowa
Product Szafir SDK
Weakness CWE-637
Published May 25, 2026
Last update May 26, 2026

CVSS base score

9.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Szafir SDK returns a success status code from the cryptographic digital signature verification process (i.e. /VerifyingTaskItem/Signature/VerificationResult/Result/@code == 0, "Positively verified") even when the trust status of the signer's certificate could not be established (i.e. /VerifyingTaskItem/Signature/VerificationResult/SigningCertificate/@certificateType == "nondetermined"). This causes consuming applications to incorrectly treat the signature as valid despite an unverified certificate chain, enabling authentication bypass and user impersonation. This issue was fixed in version 463.

Key dates

02Disclosure timeline

May 25, 2026 CVE published
May 26, 2026 Record updated